A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of preparing for an event. It sets the stage for what needs to be done first. It does not refer to any previous information, which makes it independent. Why other lines are not chosen? Paragraph 2 starts with "A well-thought-out menu..." which is specific and does not introduce the topic. Paragraph 3 starts with "Following this..." which refers to something before it, so it cannot be first. Paragraph 4 starts with "Finally..." which also indicates it is not the first sentence.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the ideas about preparing for the event. It uses the word "Finally" which signals that this is the conclusion of the preparation steps.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it continues the theme of preparing for the event. The phrase "A well-thought-out menu" follows the idea of planning, making it a logical next step.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 because it shows the next action after planning the menu. The phrase "Following this" indicates that grocery shopping is the next step in the preparation process.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it describes the final touches after preparing the food. The word "Finally" shows that this is the last step in the preparation.